Power transmission systems are used to selectively deliver rotational power from a driver such as an internal combustion engine or other source of rotational power, to a driven device. Driven devices may commonly include such things as pumps, electric generators, winches, chippers, the tires of a vehicle or the propeller of a watercraft. Clutches are used to selectively engage and disengage the driver from the driven device.
Mechanical clutches commonly operate to selectively engage and disengage the driver and driven devices by having a stack of adjacent clutch discs. The discs in the stack, which are also referred to herein as discs of a disc pack, selectively mechanically engage the driving and driven members. The axial force that acts between the discs can be selectively varied. When the clutch is not engaged, the discs that move with the driving member are sufficiently disposed from the discs that are engaged with the driven member such that they can rotate relative thereto. To engage the clutch, the discs in the stack are axially compressed such that the discs connected to the driving member are in pressurized abutting engagement with the discs connected to the driven member. As a result, the driven member is caused to rotate with the driving member, and the driven device is engaged with the driver.
Mechanical clutches commonly experience certain types of issues which limit their capabilities and useful life. These include wearing of the clutch discs over time with repeated engagement and disengagement of the clutch. Other issues may include providing sufficient axial force to the discs in order to transmit the level of power needed to operate the driven device. Other issues include avoiding excessive heat which can shorten the life of clutch discs and also limit power transmission capabilities. Other issues include shock and jarring which can damage driven devices when clutches are rapidly engaged. Additional problems and drawbacks can be encountered with mechanical clutches and systems depending upon the particular system in which a clutch is used.
Mechanical clutches and related systems may benefit from improvements.